Calcining method and apparatus



' June 16, 1925. 1,542,647 c. F. SPARKS CALGINING METHOD AND APPARATUS Filed June 12, 1922 Patented June 16, 1925.

UNITED STATES CHARLES F. SPARKS, OF ST. LOUIS, MISSOURI. I

CALG'INING METHOD, AND APPARATUS.

Application flled June 12, 1922. Serial N6. 567,855.

To all whom it may concern:

Be it known that I, CHARLnsF. SPARKS, a

citizen of the United States, residing in the city of St. Louis and State of Missouri, have invented new and useful Improvements in Calcining" Methods and Apparatus, of which the following is a specification.

This invention relates to calcining methods and calcining apparatus, and the general object of the invention is to provide a simple method and means for. effecting the calcining operation in such a way as to enable the heating medium to be broughtinto olose contact with the material being calcined; also to provide means for effecting the cooling of 'the material, if desired, before removing the same from the calcining chamber. A further object is to provide apparatus which can be controlled in operat1on so as to insure that the material will besubjected to the desired temperature for anyjdesired length of time.

Further objects of the invention will appear hereinafter.

The invention consists in the novel features, and 1n the. general combinatlon of parts to be particularly, described hereinafter, all of which contribute to. produce a simple and efiicient calcining apparatus. A preferred embodiment of my: invention will be particularly described in the follow ng specification, while the broad scope of my invention will be pointed out in the append+ ed claims; 7 g

. The inventionalso resides .in the novel steps and combination ofsteps involved in my novel method, allot which will be described in the, following spe'cifiction and set forthin the claims upon the method.

In the drawing- Figure 1 is a side elevation and partial section of my novel apparatus, by means of which my method may be practiced;

Fi ure 2 is a cross-section taken'about on the line 22 of Figure 1. j

In practicing ,my method, I advance a mass ofthe material to be calcined through the calcining' chamber, and I obstruct the path of the same at. a plurality of points on lines passing" transversely through the mass, thereby I forming. ducts at I the obstructed points; the Walls of these ductsare formed partly in the material being calcined; I then pass a heating medium throu h the ducts and in directcontact with the material to be calcined In this' way,

the heat is Very effectively and efiiciently applied for my purposes.

g I prefer to obstruct the movement of the material at threeseparated points on transverse lines disposed apart along the line of movement of the material so as to produce three transverse ducts in the material at the obstructed points; I then pass a heating medium, such as hot air or gas, at a rela tively'ilow temperature through the duct which is adjacent to the first obstructed point, and I pass-a heating medium at a relatively high temperature through the second duct which is reached by the material in its movement. In this way, the'material is first subjected tolthe relatively low temperature and then to. the relatively high temperature. Through the third duct, I pass a cooling medium which reduces the temperature of the mate-rial so that it can be removed from the calcining chamber atv any desired temperature. I shall now. de-

scribe my novel apparatus which is well adapted for carrying out my method.v

This apparatus is very simple and com prises a calcining chamber 1 which may be provided with a hopper 2 above so aslto enable the material to be calcined, for eX- ample fullers earth, to be introduced into the calcining chamber from above. The

side wall of the cha-mber near the bottom may be provided with flap doors 3 through which the calcined material may be removed, thereby enabling the material above to'a-dvance or'move downwardly by gravity through the c'aloiningchamb'er.

In order to obstruct the movement of the calcining. material at av plurality I of points, I provide a plurality of sheds 4 4 and 4.

These sheds are constructed so that they extend transversely across the path of the material as it descends, and are so constructed that-they co-operate with the material 5 to produce ducts in the spaces under .the sheds." I prefer to construct these sheds of .angle iron with the apex of the angle disposed upwardly, the flanges of the angle being disposed on an angleof45 in each di' rection so as to shed the material in both ways. :It being understood that the mate rial completely fills the chamber and hopper,

it will be evident that the material tends to flow in under the shed-s so that under each shed, a large part of the wall of the duct 6 1s compo ed of the material; I prefer to "arrange meshed; 4r, 4f, 4 in vertical sets and for the purpose of illustration, I have shown three such sets (see Figure 2). The sheds of the two outside vertical rows are disposed in a staggeredrelation with respectto the middle vertical row. It should be understood however, that each vertical row operates substantially as a unit, and the number of units employed would be determined by the desired capacity for the calcining chamber. As the material comes down, it comes in contact first, with the shed at and then with the shed t and at last with the shed l.

According to my invention, I provide means for passing a heating medium through the duct 6 under the shed l which is at a relatively low temperature as compared with the heating medium which I pass through the corresponding duct under the shed 4 In this way, I subject the material first, to a'relatively low temperature and then to a relativelyhigh temperature. In practice, I accomplish this by providing gas-burner 7 or other suitable means for introducing a heating medium. In the presentinstance, the end walls 8 of the calcining chamber are provided with triangular openings 9 which receive the endsof the sheds. The flame at the gas jet 7 entrains air at the. adjacent end of the duct 6,-and a relatively high temperature is produced in the mixed hot air and gases of combustion as they pass toward the other end of the duct under the shed 4;". The space under the shed 4 is connected with the space under the shed 4c sothatafter' traversing the duct under the shed 4 the heating medium passes up and into the space under the shed 4 In order to accomplish this, I prefer to connect theopenings 9 corresponding to these two sheds by a bonnet 10' (see Figure- 1). In this way, after parting, with a large part of their heat, the hot gases and air pass back under the shed 4 ,.and, thence, pass out to the atmosphere through the wall of the chamber. i i

While I ha've illustrated a single duct or pass for the hottest gases and a si'n 'le duct orpass for the return of the same after] they lia'velost a part of their heat, it should be understood that, if desired, I may pass and repass thesega's'es as often as necessary; the

practice as to this would depend upon the peculiar nature of the calcining problem and alsoupon the kind of material being treated. n

hprefer to providejmean s for effecting the cooling of the calcining material before removing from the calcining Chamber, and forthis purpose, the aforesaidirlower shed i is'provided- If desired, a cooling medium may be sent through the duct 6 under this shed, but under most circumstances sufficient. cooling effect will result it the ends of this" duct are simply left open to the atmosphere by extending the sheds to the openings 9 in the end wallsof the chamber.

In the calcining or tempering of lullers earth, it is desirable to know with substanthese tubes, I may insert thermometers which will indicate the temperature in the vicinity of the upper and lower sheds l" and 4'. By observing these thermometers, the operator of the apparatus may be intelligently guided iutlie regulationof the temperature of the heated medium which is admitted to the heating ducts under the sheds l and 4.; And by withdrawing the calcining material at a certain rate, can readily be calculated just what length of time the material has spent in passing through zones of difierent temperature. In this way, it becomes possible for the operator of this apparatus to certify positively as to the length of time the earth was subjected to a certain temperature or certain temperature limits.

The use of angle irons toconstruct the sheds is advantageous because this shape produces a channel on the underside of the shed so that the space under the sheds operates as a flue to guide the hot gases. I

Vhile a large partof the calcining effect is produced by subjecting the material to direct contact with the heated medium, of course, considerable calcining-efl'ect is derived from the high temperature of the metal of the sheds. Of course, the sheds will come in direct contact wer large amount, of the. material as it moves down the calcining chamber; It is desirable of course, that they should be constructed of heat-conducting material such as steel or iron.

It is understood that theembodiment of the invention described herein ison ly one of the many embodiments my invention may take, and I do not wish to be limited in the practice of my invention nor inmy claims, to the particular embodiment set forth.

Although I have only illustrated two openings for thermometers, if desired, may provide a. similar opening abouton the level with the lower'sheds'? so as to indicate the temperature of withdrawal of the calcined material; i

I What/I claim is l r 1. In calcining apparatus thejcombination of a calciningichamber having ,a'lower outlet for withdrawin the calcined material, a transversely disposed bar extending through the chamber and presenting a chan nel on its underside to receive the heating medium at a relatively high temperature, and enable the same to come in direct contact with the material within the calcining chamber, a second transversely disposed bar at a higher level than the lower bar and presenting a channel on its underside, means for connecting the two bars so as to enable the heating medium to pass from the channel of the lower bar into the channel of the upper bar, and an angle bar extending transversely through the chamber below said first named bar and having a channel on its underside, the ends of said channel extending through the walls of the chamber and enabling a cooling medium to pass through the same and come in direct contact with the material below the bar. 2. In a calcining apparatus, the combination of a calcinin chamber constructed to be charged from a ove and having an outlet below for withdrawing the calcined material, a transversely disposed bar of heatconducting material extending through the chamber and presenting a channel on its underside to receive the heating medium at a relatively high temperature, and enable the same to come in direct contact with the material within the calcining chamber, a second transversely disposed bar at a higher level than the lower bar also constructed of heat-conducting material and presenting a channel on its underside, means for connecting the two bars so as to: enable the heating medium to pass from the channel of the lower bar into the channel of the upper bar, and a third angle bar extending transversely through said chamber below the level of the first named bar and'having a channel on its underside, and co-operating with the calcining material to form a duct therethrough, the ends of said channel extending through the walls of the chamber and enabling a cooling medium to pass through the same and come in direct contact with the material below the bar.

In testimony whereof, have hereunto set i my hand. e' 7 CHARLES F. SPARKS. 

